COPEPODS OP THE WOODS HOLE REGION 



329 



Genus ORTHOCYCLOPS E. B. Forbes, 1897 



Body rather slender; metasome elongate, twice as long as wide 

 and but little depressed ; urosome cylindrical, 4-segmented in female, 

 5-segmented in male; genital segment widened but little; caudal 

 rami longer than anal segment. First antennae 16-segmented in 

 both sexes, twice geniculate in the male, the terminal section as 

 long as either of the other two, the eleventh segment with a process 

 at the anterior distal corner; second antennae 4-segmented, without 

 an exopod. Eami of first four pairs of legs 3-segmented ; fifth leg 

 also 3-segmented, the basal segment unarmed, the second segment 

 with one outer seta, the end seg- 

 ment with two very long subequal 

 setae. Two ovisacs; eggs of mod- 

 erate size. A single species. 



ORTHOCYCLOPS MODESTUS (Herrick) 

 FiGXJBE 196 



Cyclops modestus Herrick, Amer. 



Nat., vol. 17, p. 500^ 1883; Copepoda 



of Minnesota, p. 108, pi. 21, figs. 1-5, 



1895. 

 Orthocyclops modestus E. B. Forbes, 



Bull. Illinois Lab. Nat. Hist., vol. 5, 



p. 51, pi. 15, fig. 4, pi. 16, figs. 1-3, 



1897. 



Occurrence. — A few specimens 

 were taken in Gosnold Upper Pond 

 on Cutty hunk Island, July, 1926. 



Distribution. — Alabama, Minne- 

 sota (Herrick) ; Wisconsin, Penn- 

 sylvania (Marsh ); Wyoming 

 (Forbes). 



Color. — Body rather transpar- 

 ent with a decided violet or pur- 

 plish tinge, especially along the grooves between the segments, the 

 metasome with a peculiar shining surface as though polished. 



Female. — Metasome broadly oval, the breadth exceeding half the 

 length; urosome, including the caudal rami, about half the length 

 of the metasome; cephalic segment one-half longer than the rest 

 of the metasome; genital segment longer than the two basal seg- 

 ments of the abdomen, with rounded lateral protuberances near 

 its anterior end; caudal rami three times as long as wide, ciliate 

 on their inner margins. First antennae 16-segTnented, longer than 

 the cephalic segment; rami of the first four pairs of legs 3-seg- 

 mented. the terminal exopod segments with 4, 4, 3, 3, spines, 



FiGDEE 196. — Orthocyclops modestus: a, 

 Male, dorsal ; &, male, fifth leg ; c, fe- 

 male, fifth leg 



